1. Field of the Invention
The present invention relates to an apparatus for producing a tube wound from a web material, including a stationary winding drum having an inner surface on which a laterally fed plastic material web is wound spirally into a tube while adjoining web edges are bonded together, including further means operative to advance the plastic material web and means operative to bond the web edges to each other, and including a plurality of rod shaped cylindrical members forming the jacket of the drum which cylindrical members extend between the two face flanges of the drum.
2. Description of the Prior Art
The production of plastic tubes by the so-called winding method is generally known. To this end a plastic web is usually either spirally wound on a mandrel or, specifically in case of larger diameters, such plastic web is formed also spirally within a drum. The spirally extending seams of abutting or adjoining web side edges are either held together and/or welded or bonded together.
The present invention is directed to an apparatus for the production of such wound tubes. Generally, such apparatuses are used in the field, i.e. the tubes are produced at the location proper where they are used. Such happens for instance at locations where damaged tubes or pipes must be renovated or repaired respectively and this by insertion of a suitably produced plastic tube. In order to accomplish this object it has been found to be specifically suitable to produce a plastic tube to be inserted for above reason also on site, i.e. at the respective location proper, and to feed the tube being formed simultaneously into the tube or pipe under repair. The corresponding apparatus is thereby inserted often from above into a shaft (man hole).
The presently known tube winding apparatuses operating with a drum are generally equipped with a massive wall drum or with a drum having a jacket formed by rod shaped, cylindrical members extending between two face flanges. In recent apparatuses such rollers have been arranged freely rotatable between the face flanges, to counteract the friction between the web or the tube in production and the inner surface of the jacket and accordingly to decrease such friction as much as possible. The friction has been decreased also by other procedures, such that for instance surfaces were employed having as small as possible a coefficient of friction or even having lubricants.